1. Field of the Invention
The present invention relates to a test system for a mobile communication terminal which has a system simulator function capable of communication-connection with a mobile communication terminal, and which is for testing whether or not a connection state of the mobile communication terminal appropriately transits among cells in accordance with movement of the mobile communication terminal among the cells by using a mobile communication terminal of a cellular system which moves among cells (units of service areas of respective base stations), and in particular, to a test system for a mobile communication terminal in which a technique is used that, when a connection-transition test in which the a mobile communication terminal is made to artificially transit among the cells and switch the connection state is executed many times, and the respective results are statically evaluated, an operator can directly and visually grasp the evaluation quantitatively.
2. Description of the Related Art
Conventionally, for example, a cellular system is known as one of the communication systems using a mobile communication terminal such as a car telephone or a portable telephone.
FIG. 7 is a diagram for explanation of the relationship among cells (service areas).
That is, as shown in FIG. 7, in a communication system using base stations inn terminal 1 such as a car telephone or a portable telephone, as the cellular system, respective base stations 11, 12, 13, 14, . . . make the mobile communication terminal 1 be able to carry out communication by registering a position of the mobile communication terminal 1 when the mobile communication terminal 1 comes into cells 21, 22, 23, 24, . . . which are the service areas called cells, respectively.
For example, when the mobile communication terminal 1 moves from the cell 21 to the cell 22, in a case where the cell 21 and the cell 22 can receive communication services from both of the base stations 11 and 12, the mobile communication terminal 1 can use incoming radio waves whose power is stronger power among the incoming ratio waves of the both cells, or can use the incoming waves from the both cells.
In this case, when the mobile communication terminal 1 moves among the cells as described above, the mobile communication terminal 1 automatically switches the connection state from the base station 11 to the base station 12 (hereinafter, this is called “a transition of the connection state”).
Accordingly, at the manufacturer of the mobile communication terminal 1, it is necessary to test in advance, before the shipping of the mobile communication terminal 1, whether or not the transition of the connection state is correctly executed in the mobile communication terminal 1, and how the communication quality is at that time, for example, the error rate of the data.
At the time of carrying out such a test, a method has been used in which the mobile communication terminal 1 itself is not moved and the position thereof is fixed, and test signals corresponding to the cells 21, 22, 23, 24, . . . are generated at the test system side, and by carrying out dummy communication with the mobile communication terminal 1 in accordance with a protocol along the communication system, the transition and the quality of the connection state of the mobile communication terminal 1 are tested.
Namely, at the test system side, a system simulator is configured, and the system simulator communicating with the mobile communication terminal 1, whereby the tests for the transition and the quality of the connection state of the mobile communication terminal 1 are carried out.
As a method for testing a mobile communication terminal in such a communication system, for example, there is an RRM (Radio Resource Management) test in accordance with the regulation described in “3GPP TS 34. 121, V3. 11. 0, December 2002, 3GPP Organizational Partners (ARIB, CWTS, ETSI, T1, TTA, TTC), France, P. 316–330” which is the test regulation in the W-CDMA communication system.
To put it simply, the RRM test is that a connection test with a base station or a procedure test with respect to a mobile communication terminal is carried out.
FIG. 8 is a functional block diagram showing a configuration of the conventional test system for a mobile communication terminal in which the RRM test is carried out.
In FIG. 8, the transmitting/receiving unit 3 has functions of respective transmitter/receivers 3a, 3b, 3c, 3d, . . . which correspond to the cells 21, 22, 23, 24, . . . of FIG. 7.
Further, the functions of the respective transmitter/receivers 3a, 3b, 3c, 3d, . . . naturally include a function of carrying out communication connection by exchanging necessary messages with the mobile communication terminal (UE: User Equipment) 1 in accordance with a predetermined protocol in the same way as in the base stations 11, 12, 13, 14, . . . of FIG. 7.
The transmitting/receiving unit 3 transmits predetermined test signals to the mobile communication terminal 1 via a connecting unit 2 by the functions of the respective transmitter/receivers 3a, 3b, 3c, 3d, . . . .
A reception measurement unit 4 has a function of confirming a transition and testing a quality of the connection state of the mobile communication terminal 1 by analyzing and measuring a response signal transmitted from the mobile communication terminal 1 due to the communication connection between the transmitting/receiving unit 3 and the mobile communication terminal 1.
Note that the transmitting/receiving unit 3 and the reception measurement unit 4 are configured so as to operate synchronously with one another in time.
Further, the reception measurement unit 4 has a function of time measurement or the like.
Because the mobile communication terminal 1 carries out transmission and reception with the transmitting/receiving unit 3 by radio propagation signals, the reception measurement unit 4 is configured so as to have a spectrum analyzer or the like which can measure the spectrum, the band, power, or the like of the propagation signals, built-in in order to test the characteristic of the propagation signal at a radio frequency region.
With respect to the time measurement at the reception measurement unit 4, a response signal from the mobile communication terminal 1 is received in response to the test signal from the transmitting/receiving unit 3, and that time is measured.
For example, the reception measurement unit 4 measures the time by carrying out time region measurement in the same way as in an oscilloscope by converting the received frequency from the mobile communication terminal 1 into an intermediate frequency by the built-in spectrum analyzer, and a time-sweeping at the intermediate frequency.
As described above, the transmitting/receiving unit 3 and the reception measurement unit 4 have both of the system simulator function and the measuring function (testing function).
In the following description, there are cases in which the transmitting/receiving unit 3 and the reception measurement unit 4 are collectively called a system simulator.
At the connecting unit 2, the mobile communication terminal 1 and the system simulator may be connected to one another in both directions by a cable, or may be connected to one another via an antenna.
A test procedure control unit 5 has a time setting unit 5a, and controls the system simulator by outputting control information including time setting information along the testing method in the above-described communication method, for example, the RRM test procedure of the W-CDMA as described above.
In particular, in the communication system as described above, when the mobile communication terminal 1 moves among the cells, this mobile communication terminal 1 completing the switching of receipt and the registering, and then transiting so that receipt of a predetermined quality is possible, within a predetermined time-passage, are determined in accordance with regulations. Therefore, the mobile communication terminal 1 must satisfy these sequential operations.
Accordingly, the test procedure control unit 5 has a predetermined procedure for causing the mobile communication terminal 1 to carry out the sequential operations along the regulation via the system simulator.
When the system simulator is operating in accordance with the setting at the time setting unit 5a of the test procedure control unit 5, a deciding unit 6 decides whether or not the transition, among the cells of the connection state at the mobile communication terminal 1 is being carried out within a predetermined time by repeating the test many times, for example, 1000 times.
The deciding unit 6 statistically determines the results of the repetitive decisions, and outputs the final test results as numeric data to an indicating unit 9 or the like.
In the test system for the mobile communication terminal according to the prior art, an indication on the indicating unit 9 depends on the numeric indication by only numeric data in accordance with each measurement item.
Accordingly, in the test system for the mobile communication terminal according to the prior art, for example, the rate of the successes (pass: success in separating from one cell and connecting to the other cell) and the failures (fail: error in separating from one cell and connecting to the other cell) of the scheduled transition of the connection among the cells at the time of repeating testing 1000 times, is numerically indicated.
Further, in the test system for the mobile communication terminal according to the prior art, there are cases in which the rate of failures exceeds a predetermined allowable range, and in which the number of times thereof is indicated numerically, and the like.
However, in the test system for the mobile communication terminal in accordance with the prior art as described above, the indication of the test result of the transition test or the like of the connection state, by the system simulator, of the mobile communication terminal depends on the numerical indication by only numeric data. Therefore, there is the problem that the operator cannot directly and visually grasp the final test result quantitatively, and cannot grasp how the result of the test in progress were, and what movement and what tendency the result of the test in progress will show from this time force.